Endometrial shedding is a normal physiological phenomenon, which refers to the shedding of the endometrium in response to the cyclic secretion of hormones by the ovaries, also known as menstruation, which occurs in cycles ranging from 21-35 days. The first half of the menstrual cycle is the follicular phase, in which the follicles gradually grow, estrogen and progesterone gradually increase, and the endometrium gradually thickens. The middle of the cycle is the ovulation phase, when the ovaries can discharge mature follicles. If no conception occurs, the ovarian corpus luteum will gradually atrophy and decline in function, resulting in a decrease in estrogen and progesterone, and the endometrium will peel off when it loses hormonal support, after which it will menstruate and enter the next menstrual cycle. Of course, there is also abnormal endometrial exfoliation, mainly refers to breakthrough bleeding, mostly seen in menopause or adolescence, the ovarian function is still immature or began to decline, there is no regular ovulation and estrogen and progesterone changes, there is no regular menstruation, the endometrium under the action of a single estrogen gradually thickened, thickened to a certain extent, causing endometrial exfoliation, there will be breakthrough bleeding, is abnormal Endometrial exfoliation. This type of endometrial exfoliation is often irregular and can cause heavy vaginal bleeding. Breakthrough bleeding during menopause requires curettage, which is both hemostatic and diagnostic, and the uterine scrapings are sent for pathologic testing to clarify the presence of endometrial lesions. For breakthrough bleeding and vaginal haemorrhage during puberty, medication is given to stop the bleeding by giving larger doses of estrogen and progestin, followed by smaller doses of estrogen and progestin to adjust the menstrual cycle.